Dimensions - High Efficiency motor dimensions can differ from previous standard sizes. The motors will generally be longer to accommodate for larger stator cores.

Eff Standard - Customers have to rely on suppliers published performance data in respect to purchase & calculations. South Africa do not have a proper Efficiency standard that suppliers have to conform to or have their motors tested against. In a recent independent test conducted by a large corporation it is apparent that there a definitely a concerned variation between suppliers published data & actual tested data.

WEM Electric is a member of the SABS Efficiency Forum which has recently published it’s draft specification for motor efficiency.

Approved repair - Does your company have a Approved Repair Company – High

Efficiency repairs require special procedures & attention.

(Repair maintenance records and tests provide vital information for

either replacement or repair decisions.)

If no specified repair plan or procedure is in place with your approved armature winder which specifically covers the rewind or repair of a High Efficiency motor, one should then possibly spare the extra expense of purchasing a High Efficiency motor in lieu of a standard motor.

Should you purchase a motor from a reputable supplier, correctly sized, applied and installed and it is operating under the conditions for which was designed you will have no reason to be concerned about overheating.

It is generally accepted that a High Efficiency 2 motor with regards Efficiency, Power Factor and cost is the most economical and widely accepted standard of High Efficiency motor currently in use in the world today.

The added cost implication of between 30% to 45% to increase from a Efficiency 2 to Efficiency 1 motor compared to the minimal improvement in efficiency has prevented Industry in Europe and

other industrialised countries to implement Efficiency 1 motors as standard.

Hi Grant / Danie May you please give me a quote for the induction motor. Find attached technical details/specifications of the required motor.NB!!! This motor must be able to work on the VSD application, i.e must have insulated bearings to prevent high temperature bearing failure.Regards Michael Afrox Reliability and Maintenance

Hi GrantHope you are well. I attached pics of a 355kw , 6.6Kv motor that we use on site. They were custom made for us. We would like more spare motors. Please have a look at the pics and let me know if you guys can modify another motor to suit ours . Regards Nick Mine Ugabda

Hi Andre/ DanieMay I request a quotation on a control box complete to fit a 45KW motor please? Or for a Star-Delta starter complete with a timer and an overload protector to fit a 45KW motorThanks Nelly - SABMiller

Hi Grant / DanieJust want to inform you and thank you the 373 kW 6 Pole 3,3 kV D450 Frame TEFC Squirrel Cage Motor you supplied to us on an Super Emergency Breakdown, is up and running, thanks again for the Great Service Regards Chetan Senior Electrical Engineer Sasol Mining

Could you please send me a quotation for the motor with details below. from the information l have, you supplied the same motors to Kadoma City Council a few years back.Frame 5009P Volts 3300Amps 63 Hz 50 RPM 1465 Thanks Tapiwa

Hi Grant

Thanks for the info, RBM system has facility for a single (one) e-mail address, please advise which e-mail, p o box, physical address and contact person you would prefer RBM to use Regards Tracey Richards Bay Minerals

I received better prices from Indusquip WEM , please advice If I can process this requisition on them?Celia Technical Buyer Lonmin

Hi Louis can we invite Indusquip for new HT Motors in the future . We have requested quotes from Indusquip on HV Electric Motors and they have supplied our Group New 1550 kW NEW WEM Squirrel Cage motors and quoted on AC Drives before, from the Tender dept. side Regards Peter Harmony Group Demand Management

Hi GrantAttached is the order for the 3 off 55kW pumps for delivery to 35km outside Brits as discussed.Regards Peter, PPC Cement

Monday, September 27, 2010

Hi Grant,How are you guys doing back there in SA?Looks like your business has really taken off, good for youguys, well done and I hope it continues! From Neil Spiers - Ex Anglo American South Africa now residing overeas. (22 Sept 2010)

Hi Grant , your 450 kW 6 Pole 6,6 kV Slip Ring motor is running beautifully .Thank you for your support and hope to do business with you again. Thanks Sunil (Large Company RSA South Coast)

Hi Grant!!Could you please supply me with a quotation on a 1.5kW 230V and a 2.2kW 230V AC drives, as we use those sizes the most in our factory. Thanks Wiseman

Hi Grant Thanks for the call. You shall always be recommended to clients.Regards, Arnie Sasol Secunda

Hi Grant I trust you are well. Please could quote me on: 3x 330kw/6.6kv motors for water pumping duty
1. standard motor.2. high efficiency version.3. with AC drive/softstarter etc.Re your energy-savings ‘drive’, you should come to us for a visit our Projects we have quite a few projects in design/estimation phase we need your help to spec things in now. Also have a dedicated ‘Energy Manager. Hansell Williams Diamond Mining

Hi Grant / Wulf Can you urgently quote on New WEM AC Drives1. 630 Kw VSD, 550v, 50Hz, 2.55 Kw VSD, 550v, 50Hz 3. 45Kw VSD, 550v, 50 Hz• The 45 and 55 kw vsds are for driving rotary screw compressors.• The 660kw vsd is for driving a cursher. Both drives are four pole drives.for the compressor drives the maximum cable length put it at 5m, and for the crusher drive put it at 10m.Our ambient temperature is 30 degrees and the worst case temperatures can reach 40 dgrees, this is an outdoor application so the drive will be housed in an outdoor enclosure. as for the communication you can quote me for profibus. Thanks Wellington

Hi Grant, Thanks for the info, I will contact you in the event of us requiring anything.Thanks Hein Large Paint Manufacturer

Hi GrantWE are looking for a 600kW 8 Pole, 11kV motor for a Ventilation Fan for use underground, do you have any second hand motors available. A motor of up to 750kW would also be ok for the application. Thanks Regards Tom Large Project House

Hi Andre / Wulf I Have a project where i need to install a braking system on a 37 kw motor , please let me know if you can supply me with the brake or would it just be better to buy the complete new system ( brake and motor ) . I have attached the drawing the client has sent to me, the supply voltage to the brake must be 525vac Thanks Stephen

Hi Helene, Please advise on delivery date on the following order This will be much appreciated Regards Sheree Murray & Roberts

Hi Grant,Is there any possibility for a sole Distributor / Agency in the Middelburg/Witbank area? My company is looking for a partnership in the electrical motor industry - Sorry Collisens Electrical are our Agents in Witbank Middelburg and Collisens are doing a gfantastic Job. Regards Grant

Hi Gant
I require a motor to operate a Hazemag AP-KV0805 type crusher in a mining environment.
IMS the suppliers of the crusher say I require a 110 kW, 4 pole, 50Hz electrical motor with VSD / frequency converter with starter and control panel.Can you price the motor & do you supply VSD’s control panels etc Regards Peter

Hallo Grant Here is the motor specs as per our conversation: 900KW, 4P ,660V , FRAME-1LA1 503-4 , (two are in operation ) we are urgently looking for the front end shieldRegards Peet Lafarge Industries South Africa

Hallo Guys
We at PPC are in the need of a 55 / 60 KW (70 BHP) Slipring motor.
Please let me know if you got any or if you are able to get one and the price of such a unit.Thank you very much for your co-operation. Regards Nols PPC

Afternoon, Grant and Danie

Please find attached the request to submit your quotes for the supply of 1000kw 6,6kv motor as per attached specification.Rrgards Nokuthula Harmony Gold

Alternating-current (AC) and direct-current (DC) motors have traditionally served distinctly different applications due to their construction and inherent operating characteristics. In general, AC motors were smaller, less expensive, lighter and more rugged than DC motors. DC motors, on the other hand, operated better in variable-speed applications, particularly those requiring wide speed ranges, and provided more precise speed control.

DC motors have been the workhorse of industry in many applications where variable-speed operation is needed. In these applications, DC motors are reliable and provide precise speed control under variable operating conditions. However, DC motors are expensive to purchase and to maintain. In addition, over the past 10 years, AC drives have improved to the point where their speed control is far more precise, rivaling that of servo drives. What's more, the AC motor and drive together often cost about the same price as the DC motor alone.

THE RISE OF AC DRIVES

AC drives use a solid-state, adjustable-frequency inverter that adjusts frequency and voltage to vary the speed of an otherwise fixed-speed AC motor. This control is typically produced through pulse width modulation (PWM) of the drive output to the motor. Voltage and frequency are maintained in a constant relationship at any motor speed (known as the volts-to-hertz ratio).

AC drives are preferred when the motor environment is corrosive, potentially explosive, hazardous or wet, and demands special enclosures (explosion-proof, washdown, etc.). AC drives are also a good choice when the motors will receive little maintenance, either because they are inaccessible or because plant maintenance practices are poor.

AC drives generally are smaller and lighter than DC drives for a given torque and speed output, and they are capable of speeds approaching 10,000 rpm. In addition, a single AC drive can control multiple motors.

Modern AC motors and drives provide a number of additional operating benefits that rival those traditionally available only from DC drives. For example, today's drives can now produce full torque at start-up, something that once was impossible. They also are capable of speed ranges of 1,000:1 vs. only around 10:1 with previous AC drives.

Variable-speed AC drives also can adjust to fast-changing loads and provide tight speed regulation. When operated in closed-loop systems, AC drives can regulate speeds to within 0.01 percent and less. This makes them suitable for applications requiring high dynamic response, such as web processes, material handling sorter conveyors, metering pumps, extruders and test stands. The table on the next page compares the capabilities of standard DC motor drives and modern variable-speed AC drives.

Improved control technology is the reason for the vast improvement in AC drive performance. Today's inverters are smaller, less expensive, and they provide more capabilities than a few years ago.

Although AC motors have been capable of operating over huge speed ranges for some time, the drives available could not match their performance. Now, AC drives can produce near-servo-drive performance in a compact, reasonably priced package

The development of modern AC motors and drives is blurring the distinctions that once governed the choice between AC and DC drives. The result is that lower-cost, more-reliable AC drives are moving into applications once reserved for DC drives

SPEED CONTROL EFFECTS

AC motors have traditionally operated at fixed frequency and speed. At this speed, the built-in cooling system keeps the motor from overheating. Operating an induction motor as a variable-speed motor increases operating temperature and places increased stress on the insulation system. The higher temperatures result from increased motor losses and reduced heat transfer. As a result, many standard-efficient, fixed-frequency motors will not produce their nameplate rating when operated by an adjustable-frequency control. The elevated temperatures may not lead to immediate insulation failure; however, they will shorten life considerably.

In most insulation systems, a 10-degree Celsius increase in operating temperature will reduce expected life by 50 percent. This is one reason why energy-efficient or premium-efficient motors, which operate at cooler temperatures under the same conditions of service, are often recommended for operation with adjustable-frequency drives. Another reason that adjustable-frequency, drive-controlled, fixed-frequency motors operate at higher temperatures is that the cooling fan operates directly off the motor shaft. Thus, as motor speed varies, so does fan speed, resulting in lower cooling at slower speeds.

When operated as adjustable-speed devices, motor cooling will be reduced at slower speeds. In such applications, the motor should be specifically designed for variable-speed operation. AC variable-speed motors usually state their speed range. If you apply the motor within the specified speed range, overheating should not be an issue
OTHER CONSIDERATIONS

When system performance requirements are minimal, a standard AC induction motor often can be applied successfully in adjustable-frequency, variable-speed applications. However, when performance requirements are more demanding, an energy-efficient, premium-efficient or definite-purpose inverter-rated motor must be used. This is particularly true when maximum productivity is required.

While the definition of high-performance is indefinite, one or more of the following factors usually characterizes such applications:

•A process that cannot be started or run without variable-speed control.

Some AC motors are designed specifically to run on AF power and can provide continuous constant torque down to zero speed (1,000:1 turn-down). These designs are available in traditional totally enclosed, fan-cooled (TEFC) National Electrical Manufacturer's Association (NEMA) frame ratings or in very power-dense designs that look similar to the traditional square-frame DC. These power-dense designs are cooled with an auxiliary blower (force ventilated or blower cooled) or totally enclosed, fan-cooled construction, which eliminates the blower.
In higher horsepower ratings, these power-dense, blower-cooled designs represent a considerable cost saving vs. traditional fixed-speed motors. In addition, motors designed specifically for inverter-duty, high-performance applications have greater speed range, offer higher overload capability, and include thermal protection and mounting provision for speed-regulation devices.

Maintenance technicians at a glass plant recently witnessed first hand how high temperatures can affect and potentially damage rolling bearings. Bearings in a fan used to evacuate superheated air during the glassmaking process began to overheat. Bearing temperatures, which normally hovered around 170°F (77°C), climbed to 195°F (91°C). While the fan continued to run, plant technicians consulted with a bearing engineer to devise a solution. But their efforts came too late: by the time the meeting ended, the grease inside the bearing had dried up and smoke had begun to emanate from the bearing, causing shutdown.

Failure analysis quickly pinpointed a cause: process temperatures of 1000°F (538°C) or more produced in the glassmaking process resulted in an ambient temperature of 220°F (104°C). The plant immediately took steps to shield fan bearings mechanically from the worst of this heat. In addition, the "floating" bearing in the fan arrangement was offset in the housing, providing it with more room to travel axially to accommodate shaft expansion.

Higher-than-normal operating temperatures, whether caused by ambient conditions or generated within the bearing itself, have the potential to harm rolling bearings. Normal operating temperatures differ, depending on the application. Maintenance technicians should be aware of this and know the common causes of, and remedies for, bearing overheating.

Overheating in electric motor bearings is generally lubricant-related. For example, when relubricating open bearings, users may inadvertently employ a low-temperature grease which does not provide adequate viscosity at the normal operating temperature. Or the user may over-grease the bearing, forcing bearing balls to push through excess grease as they rotate, leading to a sharp temperature rise. Another cause of overheating is mixing incompatible greases, which can reduce the consistency of the grease and possibly the overall viscosity.

Fans

Commercial fans generally utilize ball and roller bearings mounted in cast iron or pressed steel housings. Fans are exposed to a wide variety of ambient conditions, ranging from below-zero temperatures for rooftop fans to extremely high temperatures for fans used in industrial processes.

Normal bearing operating temperatures vary, depending on the environment and application. The standard grease in most fan bearings remains effective to an operating temperature of 180°F (82°C). If steady-state operating temperatures are higher than 180°F (82°C), consider using a grease with a synthetic base oil. Viscosity in a synthetic oil does not vary as much with temperature as in a standard mineral oil, and the rate of oxidation is much slower. For operating temperatures above 200°F (93°C), a circulating oil system may be needed. These systems pump clean, cool oil through a bearing arrangement.

In hot-gas fans, special measures must be taken to protect bearings from high temperatures. In virtually all cases, an aluminum disk or flinger placed on the shaft between the bearing and the fan casing can act as a heat shield. Often, a blower wheel or compressed air can be used to direct cooling air across the bearing housing or the shaft.

Pumps

Depending on the application, normal bearing operating temperatures in pumps range from 100°F (38°C) to 180°F (82°C), with most running between 140°F (60°C) and 160°F (71°C). Although grease is used in some vertical pumps, oil is the preferred lubricant in the majority of pump applications. Standard bearing oils in pumps remain effective to approximately 180°F (82°C). If normal operating temperatures are higher than 180°F (82°C), a synthetic oil should be used; if temperatures exceed 200°F (93°C), a circulating oil system will probably be required.

As in other bearing applications, higher-than-normal operating temperatures in pumps can be caused by bearing overlubrication. Overheating can also be caused by bearing misalignment or ball skidding within the bearing. Specially designed bearings are available to eliminate ball skidding. Ideally, bearing temperatures in pumps, especially those in critical applications, should be regularly monitored.

Gear Drives

Bearings in gear drives normally operate at 160° (71°C)-180°F (82°C) and are lubricated with static oil systems. As improved technology permits reductions in the size of gear drives, there is a growing trend to transmit more power through a given size drive than ever before. This practice can cause bearings in gear drives to run hotter and may necessitate the use of alternative cooling methods.

In summary, proper bearing lubrication is the primary concern in all high-temperature applications. That concern is heightened by the trend of running industrial equipment at higher speeds than originally intended, further increasing bearing temperatures. The general rule is to provide the minimum viscosity required at the expected operating temperature: 100 SUS (20cst) for roller bearings and 70 SUS (13cst) for ball bearings. In addition, the increased thermal expansion of the shaft must be accounted for both axially (to ensure that high thrust loads are not induced) and radially (to ensure that radial internal clearance is adequate to avoid preload). The solution may also entail using a grease with a synthetic base oil or converting to a different lubricant delivery system, such as circulating oil

The VSD represents technology that boosts the performance of an electric motor and saves energy. VSD's enable more cost effective production, reduce the greenhouse effect, a play a part in meeting emissions targets. Despite this, less than 1 in 10 electric motors in the world is fitted with a VSD - financially it would be justified to install a VSD on at least 1 in 3 electric motors

Typical Applications for Industrial Plants:

•FD, ID, Primary & Secondary Air Fans

•Boiler Feed, Chilled Water, River Water Pumps

•Compressors

Typical HVAC Applications:

•AHU Fans (VAV & CAV Systems)

•Supply & Extract Fans

•Heating & CW Pumps, Duty/Standby Pump Sets

•Compressors & Chillers

Typical Applications for Leisure and Commercial Buildings:

•Swimming Pool Pumps & Ventilation

•Sports Halls, Gymnasiums & Dance Studios

•Fountains

•Ice Rinks

Some facts…

•Electric motors consume 64% of all non-domestic energy consumption

•Total population of electric motors >10 million

•3000 motors purchased everyday – most used on fans, pumps and compressors

•Rmillions could be saved through careful management

How does a VSD save energy?

A VSD regulates the speed of the motor, and in turn the speed of the pump or fan, by controlling the energy that goes into the motor, rather than restricting the flow of a process running constantly at full speed. Running a motor at full speed while throttling the output is like driving a car with one foot on the accelerator and the other on the brake; a part of the produced output immediately goes to waste. A VSD can save over 60% of the energy as it controls the energy at source, only using as much as is necessary to run the motor with the required speed and torque - much in the same way as the accelerator in the car controls the engine revs.

In particular, VSD’s can dramatically reduce energy consumption in fan and pump systems. The power required to run a centrifugal pump or a fan is proportional to the cube of the speed. This means that if 100% flow requires full power, 75% requires 0.753= 42% of full power, and 50% flow requires 0.53= 12.5% of the power. As a small reduction of the speed can make a big difference on the energy consumption, and as many fan and pump systems run at less than full capacity a lot of the time, a VSD can make huge savings compared to a motor driving an load under mechanical control.

A VSD can also make it possible to stop a motor completely when it is not required as re-starting with a VSD causes far less stress than starting direct-on-line - soft starting is an inherent feature of the VSD. Regulating the motor speed has the added benefit of easily accommodating capacity rises without extra investment, as speed increases of 5-20% is no problem with a VSD as long as there is enough spare capacity in the system.

WEM ELECTRIC MOTORS &; INVT AC VARIABLE SPEED DRIVES

INDUSQUIP WEM,have been involved in the Electic Motor Business for more than 30 Years, Privately Held by Three Major Shareholders of Indusquip Wem Electic Motors and Drives, We are leaders in the Low and High Voltage Electric Motor an AC Drive Market in South Africa, Africa, we also export our products Worldwide. THE WEM DIFFERENCE IS, WE WANT AND VALUE YOUR BUSINESS, we also have the BEST PRICED products and SHORTEST DELIVERY LEAD TIMES in the business. Feel free to contact me on my cell 0826525001 Grant or 0826525002 Burt ENERGY SAVING EXPERTS

Pedro a longstanding mate, is looking for work in the New Aluminium Windows - Building Maintenace Business, New Building & Building Renovation Business - Based In Johannesburg South Africa - Tel 0825722385 or email him at p.moutinho@mweb.co.za also loves cycling, soccer coach

Fax: +27 (086) 273 5754Mobile: +27 082 444 7802 lerouxv@kmn.co.za - Photocopiers - Based in Midrand South Africa - Best Prices - Highest Quality and amazing Service, The Best in best in the Business - A very longstanding mate, who loves cycling and boating